Abstract: We propose to continue development and support for the UltraScan-III (US3) software suite, a comprehensive toolkit for the analysis of data from hydrodynamic experiments and hydrodynamic simulations. Such experiments include analytical ultracentrifugation, small angle X-ray and neutron scattering experiments, as well as bead model simulations. Support for this project will assure future availability of a mature multi-platform analysis suite with important and unique capabilities not found in any other software packages. Chief among them are tight integration of supercomputing capabilities, LIMS support for collaboration, and specialized analysis routines. US3 enjoys widespread use in the AUC and SAXS/SANS communities, and offers the most robust optimization and simulation algorithms available, resulting in unmatched detail, and provides the highest throughput, a flexible, modern GUI, and a comprehensive list of analysis routines. Among the proposed developments are support for the next generation of three new multi-wavelength detection capable AUC instruments which will enable paradigm-changing solution studies of complex systems where components with distinct chromophores can be simultaneously separated based on both their spectral and hydrodynamic properties. Further enhancements include many algorithm improvements, porting of AUC and SOMO codes to the latest 3rd party C++ frameworks, supporting new operating systems such as 64-bit support on Windows, and enabling uniform integration of UltraScan-SOMO in the US3 class libraries.